Products and methods have been proposed and developed in an attempt to facilitate locating lost or misplaced items such as remote controls for televisions and stereos, keys, and glasses. Similarly, locating and tracking technologies have been applied to packages for shipment tracking and in object theft prevention. These technologies include complex optical scanning systems, magnetic coding, microwave systems having transmitters and receivers, infrared systems, line-of-sight type systems, mechanical systems requiring physical contact with the object to be sensed and mechanically coded interactive systems of keys in combination with the parts inside a lock.
These systems are used, for example, to locate a lost television remote in a room by causing the television remote to emit an audible signal that can be heard in the room. Typically, such locator systems use a reverse line of sight arrangement to locate the remote. Wireless telephone handsets that have been removed from a cradle can be located in a house by paging the handset to produce an audible signal that can be heard by the person looking for the handset. Both of these locator systems are specific to the objects being located and merely produce an audible signal to announce the location of the misplaced device. The object must be within the range of the locator, i.e. television or phone cradle, and the person looking for the device needs to be close enough to the lost device to hear the locator signal.
Object locating and tracking systems have been developed around technologies that use tags placed on the objects to be tracked and a scanner or reader to recognize the tags and to read information stored on the tags. These tags can either be active transmitting devices or passive devices. Examples of applications for these technologies include product inventory, grocery store checkouts, and package tracking. Each reader is generally a stand-alone, independent system capable of monitoring and obtaining information only on the objects that pass within its range. Generally, this range is very small, on the order of a few feet or less. In addition, the tags used in these systems are relatively expensive, making them suitable for expensive items but less suitable for inexpensive consumer items such as those purchased in a grocery store or discount store.
These types of tag and reader systems are illustrated, for example, in U.S. Pat. No. 3,859,624 that is directed to an inductively coupled transmitter and responder arrangement having a transmitter and a passive responder tag that receives all power from the AC power field inductively coupled thereto from the power field generator of the interrogator. The tag generates a code that is unique to the particular responder tag, and the code itself is generally a binary notation code. The interrogator receives the detected coded signal and generates an output signal which can be stored on magnetic tape for utilization in the computer, presented in a visual display, or transmitted elsewhere for subsequent utilization.
Similarly, U.S. Pat. No. 5,012,236 is directed to an electromagnetic energy transmission and detection apparatus which can simultaneously transmit a high intensity magnetic field and detect a localized low intensity magnetic field for greater distances between a reader and a passive identification tag. The reader includes a transmitter coil for transmitting a high intensity electromagnetic field to the passive identification tag and to receiver coils for receiving the low intensity electromagnetic field retransmitted by the passive identification tag to the reader. The passive identification tag includes a transponder which is capable of retransmitting a very low intensity electromagnetic field of a highly localized nature when exposed to an electromagnetic field transmitted by the transmitter coil of the reader.
U.S. Pat. No. 5,952,935 is directed to an improved programmable channel search reader that includes a field programmable serial port which may be linked to a computer by either hardware, radio frequency or the like to edit or enhance the software of the reader and if so programmed for external data logging and storage.
U.S. Pat. No. 6,184,777 discloses a passive integrated transponder tag interrogation system that is connected to a control unit that is connected to a computer through a data communication cable. The computer is a general purpose computer used to provide control to the unit, and the data communication cables include RS232 type DB 25 cables, EIA 485 metallic cables, and fiber optic cables. Wireless communication methodology utilizing digital or analog radio signals and infrared signals may also be deployed for the communication cable.
Applications for the use of reader and tag systems are illustrated, for example, in U.S. Pat. No. 3,732,465 that is directed to an electronic sensing and actuator system having a sensor and a key. The key includes interconnected passive electronic components including an electrical field sensitive circuit or circuits having a selected resident frequency or frequencies of a value within the range of frequencies of the oscillator and located in the sensor such that when the key is brought into a sensing zone, the energy of the variable frequency oscillator and the sensor is changed and that change is detected by the sensor. This apparatus has applications to door locks, and the key can also be attached to objects and used in a machine for purposes of counting or sorting objects carrying the key.
U.S. Pat. No. 3,752,960 is directed to a data acquisition system for electronically identifying and recognizing objects including systems for product handling, vehicle identification, locks and keys. The system is adapted to identify an object carrying an electrically passive circuit when the object is positioned within the effective coupling zone, but not necessarily touching, a sensor device of the active network. The passive object includes a passive reactive circuit adapted to resonate at a particular frequency when excited by the electromagnetic field of a sensor of the active part of the system.
U.S. Pat. No. 3,689,885 teaches an interrogator responder arrangement that is capable of handling random orientations between the interrogator and the responder for use in applications such as the tracking of guards, watchmen and executives in industrial plants wherein each person carries a small, inexpensive non-radiative passive responder. Interrogators are positioned at various fixed locations throughout the plant. In addition, this interrogator and passive responder arrangement could be used for the handling of luggage and cargo in airport terminals and freight terminals. In addition to a responder tag that is attached to each individual piece of luggage at the check-in station or at the ticket collection station at an airport terminal, a second responder tag having a code generation capability that provides the same code as the first responder, or bears a known correspondence to that one, is given to the passenger, and the passenger can insert the second tag into the baggage request station automatic handling equipment to detect the particular code on the tag and locate the passenger's luggage.
Other applications are directed to the use of tag and reader systems for the handling and tracking of livestock. U.S. Pat. No. 4,262,632 teaches an electronic livestock identification system containing a capsule or pill having an electronic transmitter which is uniquely coded to broadcast a series of electronic pulses from each animal in which it is internally implanted. An associated interrogator receiver unit, which is preferably situated externally of the animal, may be used for sensing and appropriately utilizing the electronic pulses to identify the animal. Although the capsule may include a power supply, it is preferably a passive storage element to which power may be induced from the interrogator.
International Application Number PCT/US87/00415 is directed to a syringe implantable identification transponder which is syringe implantable into an animal and provides identification of the specific animal when the transponder is interrogated. This transponder has particular application to the identification and monitoring of migratory waterfowl and other small animals such as fish.
Given the limitations and relatively high costs of these tracking and locating systems, an improved method for tracking and locating objects that is less expensive is desired. Suitable methods would permit a consumer to easily tag desired objects, to identify the importance of those objects, and to assign any necessary information related to those objects. In addition, it is desired to be able to track those objects across greater volumes of space and not to confine the locating and tracking of those items to fixed areas where scanners are located.